Ian elrick ewen



NOV. 2, 1965 w 3,214,818

APPARATUS FOR THE MANUFACTURE OF WOVEN CLOTH FOR ENDLESS BELTS OF PAPERMAKING MACHINES Filed Sept. 13, 1965 4 Sheets-Sheet l Inventor! IANELRICK EWEN W BY W A Horneyj NOV. 2, 1965 w 3,214,818

APPARATUS FUR THE MANUFACTURE OF WOVEN CLOTH FOR ENDLESS BELTS OF PAPERMAKING MACHINES Filed Sept. 13, 1963 4 Sheets-Sheet 2 lnvemur IAN ELRICKEWLiN A tlor'myf Nov. 2, 1965 w 3,214,818

APPARATUS FOR THE MANUFACTURE OF WOVEN CLOTH FOR ENDLESS BELTS OF PAPERMAKING MACHINES Filed Sept. 13, 1965 4 Sheets-Sheet 3 Inventor AN ELRICKEWEN WA By W A Home? I. E. EWEN 3,214,818 APPARATUS FOR THE MANUFACTUREOF WOVEN CLOTH FOR ENDLESS BELTS OF PAPER MAKING MACHINES Nov. 2, 1965 4Sheets-Sheet 4 Filed Sept. 13. 1965 Inventor'- IAN ELRICK EWEN AttorneysUnited States Patent 3,214,818 APPARATUS FOR THE MANUFACTURE OF WOVENCLOTH FOR ENDLESS BELTS OF PAPER MAKING MACHINES Ian Elrick Ewen,Granton, Edinburgh, Scotland, assignor to The United Wire Works Limited,Edinburgh, Scotland, a British company Filed Sept. 13, 1963, Ser. No.308,831 Claims priority, application Great Britain, Sept. 14, 1962,35,049/ 62 5 Claims. (CI. 26-51) This invention relates to themanufacture of woven cloth for the endless belts of paper makingmachines. Such belts are used on the wet end of a Fourdrinier papermaking machine to convey and dewater paper pulp to form a mat or sheetof fibers. The cloth may, for example, be woven with Phosphor bronzewarps and brass or Phosphor bronze wefts, or with wefts of syntheticresinous material, the belt being formed by joining together the ends ofthe cloth with the warps running lengthwise of the belt.

Due to the woven constructions, the warps form knuckles on the undersideand topside of the woven belt, and, in operation, the underside warpknuckles are subjected to severe abrasive wear as the belt travels oversuction boxes which are fitted to the paper making machine to dewaterthe paper pulp.

Under certain conditions, the warp knuckles wear grooves in the surfaceof the tops of the suction boxes, and these grooves are a replica of thelongitudinal pattern of the underside warp knuckles.

A grooved suction box top may result in. a very serious shortening ofthe life of the belt and create faults in the paper made.

In operation, there is a tendency for the belt to move to one side orthe other of the paper making machine under the action of guide rolls.When a suction box top is grooved, the belt hangs on the box and resiststhe normal lateral movement of the belt. Increasing lateral force isbuilt up by the automatic guide rolls causing severe lateral thrust onthe warp knuckles in the grooves and severe wear on the sides of theknuckles. If the belt is released from the grooves either due tosuflicicnt lateral pressure or to the presence of a discontinuity in thepattern of the underside warp knuckles, the belt slides over the top ofthe grooves which rasps the warp knuckles, causing further wear.

A grooved suction box top also causes serious trouble when a new belt isfitted. Differences in warp pattern in relation to the grooves causesevere local wear and drastically reduces the life of the belt.

This problem in the operation of paper machine belts has been known formany years by paper machine belt manufacturers, paper machine buildersand paper makers, and while various methods of overcoming the difficultyhave been proposed and practised, no complete solution has beendiscovered.

An attempt to solve the problem has hitherto been made by weaving thecloth for the belt with a slowly oscillating reed in the loom with aview to imparting a longitudinal sinusoidal curve pattern to theunderside warp knuckles. Some success has been achieved with thismethod, but it suffers from the disadvantage that, when attempts aremade to impart sufficient amplitude to 3,214,818 Patented Nov. 2, 1965the pattern with a view to ensuring non-grooving operation on the papermachine, difliculties are experienced due to variation in the mesh orweft count arising from the displacement of the reed which causesfriction against the warps in the weaving process. Also, excessive reeddisplacement can give rise to the formation of furrows in the wovencloth which cannot be tolerated for the manufacture of paper.

An object of the present invention is to provide woven cloth which, whenformed into a belt and used in a paper making machine as aforesaid, doesnot form such grooves in the tops of the suction boxes or does not reactundesirably to grooves previously formed therein.

According to the present invention we provide a meth- 0d of treatingwoven cloth for endless belts for paper making machines comprisingtensioning a length of the cloth, clamping said length of clothtransversely throughout its width at each end and midway between itsends, applying a force transversely in the plane of the cloth to theintermediate clamped portion so as to displace the warps of the lengthof cloth to a substantially chevronshaped formation, moving the clampedends further apart so as to stretch the warps while they are clamped insaid formation, and effecting said tensioning, clamping, displacing andstretching upon successive lengths of the cloth.

Further, according to the present invention we provide apparatus fortreating woven cloth for endless belts for paper making machinescomprising means for tensioning a length of the cloth, three equi-spacedclamps for clamping the length of cloth transversely throughout itswidth at its ends and midway between its ends, means for applying aforce transversely to the middle clamp so as to move it transversely andrelative to the end clamps, while the cloth is tensioned and clamped andso as to displace the warps of the length of cloth to substantiallychevron-shaped formation in the plane of the cloth relative to the warpsoutside the clamped length, means for moving the end clamps furtherapart while they are clamped in said formation so as to stretch thewarps, and means for advancing the cloth through the clamps, so thatsuccessive lengths of the cloth may be treated.

Examples of the invention will now be described with reference to theaccompanying drawings, in which:

FIGS. 1, 2 and 3 show diagrammatically successive stages of the methodaccording to the invention,

FIG. 4 is a sectional side view of apparatus according to the invention,and

FIGS. 5 and 6 are fragmentary end and plan views, respectively,corresponding to FIG. 4.

FIG. 7 shows diagrammatically in plan view woven cloth according to theinvention.

In one example of the invention woven cloth 1, FIG. 7, for forming intoendless belts for paper making machines has the warps 2 so arranged thateach forms throughout its length a series of substantiallychevron-shaped formations laterally directed in the plane of the cloth.The warps may alternatively be said to follow parallel angular zig-zagpaths.

A method of producing such cloth will now be described, by way ofexample, with reference to FIGS. 1 to 3. The cloth is woven withstraight warps, that is to say straight in planes perpendicular to theplane of the cloth. A length of cloth 3, FIG. 1, is clamped at one endby a clamp 4 and is tensioned in the direction of the warps. Thetensioned length of cloth 3 is then clamped at its other end by a clamp5, and is further clamped midway between its ends by a clamp 6, theclamping in each case being effected throughout the width of the cloth3. A force is then applied transversely of the cloth to the intermediateclamp 6 so as to displace the warps 7 of that length of clothtransversely to substantially chevron-shape as shown in FIG. 2, and thewarps 7 are then stretched by moving the clamps 4, further away fromeach other, as shown in FIG. 3. The middle clamp 6 is then released, thecloth tensioned once more by moving the clamps 4 and 5 still furtherapart, and, after rcleasing the clamps 4 and 5, the process is repeatedon contiguous uniform lengths as the cloth is fed through the clampingzones.

Apparatus suitable for carrying out the above mentioned method will nowbe described, by way example, with reference to FIGS. 4 to 6.

The apparatus consists generally of a framework 8 mounting threeparallel clamps 9, and 11, rolls 12, 13 and 14 for feeding woven cloththrough the machine, means for driving said rolls and means foractuating the clamps 9 to 11.

The three clamps 9 to 11, each having upper jaws 9A, 10A, 11A and lowerjaws 9B, 10B, 11B, are arranged one behind the other equi-spaced in ahorizontal plane and the cloth 15 extends lengthwise horizontally fromthe roll of cloth 12 at the front of the apparatus, between the jaws ofthe clamps 9 to 11, over the guide roll 13 and down to the coiling roll14 at the rear of the apparatus, the roll 14 being driven throughgearing 16 by an electric motor 17.

The front and rear clamps 9, 11 are spaced apart a distance equal toeach length of the cloth to be treated, the clamping surfaces beingnarrow and extending across the full width of the Cloth at right anglesto the warps thereof. The front and rear clamps 9, 11 are each mountedwithin a rectangular frame formed by lower beams 18, upper beams 19 andupright columns 20. The upper jaws 9A, 11A are provided on the beams 19and the lower jaws 9B, 11B are provided on beams 21 which are movableand are carried by hydraulic rams 22 fixed to the beams 18 which aremounted on the framework 8 by pivots 23 so that the clamps 9, 11 can bepivoted away from each other within predetermined limits. This pivotingmovement is effected by hydraulic rams 24 acting on vertical slides 25connected to the clamps by inclined pivoted levers 26, FIG. 4. Eachslide 25 is guided at each end by grooved rollers 27 mounted on a plate28 fixed to the framework 8. The middle clamp 10 and its supportingstructure is slidable transversely of the direction of cloth feed withinpredetermined limits under control of a hydraulic ram 29. The upper endsof the frames are urged towards each other by tension spring devices 30which are pivotally attached to the beams 19 and include screw-threadedrods 31 and nuts 32 for adjusting the tension of the springs.

The said supporting structure consists of a rectangular frame formed bya lower beam 33, an upper beam 34 and upright columns 35. The upper jaw10A of the clamp 10 is carried by the beam 34 and the lower jaw 10B iscarried by a beam 36 mounted on hydraulic rams 37 fixed to the beam 33,and the frame is slidable transversely by means of rollers 38 and 39,the beam 33 bearing on the rollers 38, and the beam 34 hearing on therollers 39.

In operation, the sequence of events is as follows;

(1) Clamp the cloth 15 with the front clamp 9 by expanding its rams 22.

(2) Tension the cloth 15 by driving the coiling roll 14 momentarilythrough the motor 17 and gearing 16.

(3) Clamp the cloth 15 with the rear clamp 11 by expanding its rams 22.

(4) Clamp the cloth 15 with the middle clamp 10, by expanding its rams37.

(5) Move the middle clamp 10 transversely to displace the warpsextending between the front and rear clamps 9, 11 to chevron-shapedformation by expanding the ram 29.

(6) Stretch the displaced warps by pivoting the front and rear clamps 9,11 further apart by expanding the rams 24.

(7) Release the centre clamp 10.

(8) Tension the cloth by moving the front and rear clamps 9, l1 slightlystill further apart.

(9) Release the clamps 9 and 11.

(10) Drive the coiling roll 14 to feed the next length of cloth to betreated between the clamps, and repeat the sequence until the fulllength of cloth required has been treated.

Suitable approximate dimensions given, by way of example, are asfollows:

WarpPhosphor bronze, 0.0096" diameter.

Weft-0.0010 diameter, per inch.

Pitch (distance between the apices of each two successive chevron-shapedformations)--35".

Amplitude (distance apex of each chevron-shaped formation istransversely displaced from the straight)- 3432"- Gradient (displacementper unit length) Cloth woven with warps and/or wefts made of a copperberillium alloy requires heat treatment, and a heating unit for thispurpose may be incorporated in the apparatus, for example, an electricalinfra red heater.

The cloth may be treated in accordance with the invention after beingmade up into an endless belt.

I claim:

1. Apparatus for treating successive lengths of woven cloth for endlessbelts for paper making machines comprising a cloth-uncoiling roll at thefront of the apparatus and a cloth-coiling roll at the rear of theapparatus, three equi-spaced clamps intermediate said rolls for clampinga length of cloth transversely throughout its width at its ends andmidway between its ends, means for engaging the end clamp nearest theuncoiling roll with the length of cloth, means for driving said coilingroll momentarily after engagement of said end clamp and prior toengagement of the remaining clamps with the cloth to tension the lengththereof, means for engaging the other end and middle clamps with thelength of cloth, means for applying a force transversely to the middleclamp so as to move it transversely and relative to the end clamps,while the cloth is tensioned and clamped and so as to displace the warpsof the length of cloth to substantially chevron-shaped formation in theplane of the cloth relative to the warps outside the clamped length, andmeans for moving the end clamps further apart while they are clamped insaid formation so as to stretch the warps.

2. Apparatus as claimed in claim 1, in which each said clamp is carriedby a frame, rollers mounting the frame carrying the middle clamp, andsaid means for applying a force transversely to the middle clampcomprises a hydraulic ram.

3. Apparatus as claimed in claim 2, in which tension spring devicesinterconnect adjacent ends of the frames carrying the end clamps, andmountings pivotally mounting said frames at their other ends so as topermit movement of said frames apart to effect said stretching.

4. Apparatus as claimed in claim 3, in which said means for engaging theend clamps with the length of cloth comprises hydraulic rams foroperating said end clamps and mounted on said frames carrying the endclamps.

5. Apparatus as claimed in claim 4, in which said means for moving saidend clamps apart comprises a slide, hydraulic rams for moving the slide,and levers interconnecting said slide and said frames carrying the endclamps.

(References on following page) References Cited by the Examiner UNITEDSTATES PATENTS Helm 2651.3 Bittner 26-51.3 Voland et a1. 26-513 Seidman139-384 Lindsay 139384 6 2,928,160 3/60 Mayer 2872 FOREIGN PATENTS25,495 11/01 Switzerland.

5 DONALD W. PARKER, Primary Examiner.

ROBERT R. MACKEY, Examiner.

1. APPARATUS FOR TREATING SUCCESSIVE LENGTHS OF WOVEN CLOTH FOR ENDLESSBELTS FOR PAPER MAKING MACHINES COMPRISING A CLOTH-UNCOILING ROLL AT THEFRONT OF THE APPARATUS AND A CLOTH-COILING ROLL AT THE REAR OF THEAPPARATUS, THREE EQUI-SPACED CLAMPS INTERMEDIATE SAID ROLLS FOR CLAMPINGA LENGTH OF CLOTH TRANSVERSELY THROUGHOUT ITS WIDTH AT ITS ENDS ANDMIDWAY BETWEEN ITS ENDS, MEANS FOR ENGAING THE END CLAMP NEAREST THEUNCOILING ROLL WITH THE LENGTH OF CLOTH, MEANS FOR DRIVING SAID COILINGROLL MOMENTARILY AFTER ENGAGEMENT OF SAID END CLAMP AND PRIOR TOENGAGEMENT OF THE REMAINING CLAMPS WITH THE CLOTH TO TENSION THE LENGTHTHEREOF, MEANS FOR ENGAGING THE OTHER END AND MIDDLE CLAMPS WITH THELENGTH OF CLOTH, MEANS FOR APPLYING A FORCE TRANSVERSELY TO THE MIDDLECLAMP SO AS TO MOVE IT TRANSVERSELY AND RELATIVE TO THE END CLAMPS,WHILE THE CLOTH IS TENSIONED AND CLAMPED AND SO AS TO DISPLACE THE WARPSOF THE LENGTH OF CLOTH TO SUBSTANTIALLY CHEVRON-SHAPED FORMATION IN THEPLANE OF THE CLOTH RELATIVE TO THE WARPS OUTSIDE THE CLAMPED LENGTH, ANDMEANS FOR MOVING THE END CLAMPS FURTHER APART WHILE THEY ARE CLAMPED INSAID FORMATION SO AS TO STRETCH THE WARPS.